foam block atop the compressor coil

I took the cover off of my old Carrier compressor (38EB060350) yesterday to clean it out with a hose. On top of the coil (and maybe the bottom too) there is a 1x1 inch piece of black foam, to block air from coming between the coil and the top of the frame (so the air comes through the coil and not around it). The foam is crumbly and I lost quite a bit of it.

What is that foam called, and where can I get it? Can I use something else to replace it? I don't suppose I can use Great Stuff spray foam?

I know, I should have taken a photo but I did not. And I have not been able to find a diagram online that shows it.